package eu.kanade.tachiyomi.ui.catalogue.browse

import android.content.res.Configuration
import android.os.Bundle
import android.view.*
import androidx.appcompat.widget.SearchView
import androidx.core.view.GravityCompat
import androidx.drawerlayout.widget.DrawerLayout
import androidx.recyclerview.widget.DividerItemDecoration
import androidx.recyclerview.widget.GridLayoutManager
import androidx.recyclerview.widget.LinearLayoutManager
import androidx.recyclerview.widget.RecyclerView
import com.afollestad.materialdialogs.MaterialDialog
import com.f2prateek.rx.preferences.Preference
import com.google.android.material.snackbar.Snackbar
import com.jakewharton.rxbinding.support.v7.widget.queryTextChangeEvents
import eu.davidea.flexibleadapter.FlexibleAdapter
import eu.davidea.flexibleadapter.items.IFlexible
import eu.kanade.tachiyomi.R
import eu.kanade.tachiyomi.data.database.models.Category
import eu.kanade.tachiyomi.data.database.models.Manga
import eu.kanade.tachiyomi.data.preference.PreferencesHelper
import eu.kanade.tachiyomi.source.CatalogueSource
import eu.kanade.tachiyomi.source.model.FilterList
import eu.kanade.tachiyomi.source.online.HttpSource
import eu.kanade.tachiyomi.ui.base.controller.NucleusController
import eu.kanade.tachiyomi.ui.base.controller.SecondaryDrawerController
import eu.kanade.tachiyomi.ui.base.controller.withFadeTransaction
import eu.kanade.tachiyomi.ui.library.ChangeMangaCategoriesDialog
import eu.kanade.tachiyomi.ui.manga.MangaController
import eu.kanade.tachiyomi.ui.webview.WebViewActivity
import eu.kanade.tachiyomi.util.system.connectivityManager
import eu.kanade.tachiyomi.util.system.toast
import eu.kanade.tachiyomi.util.view.gone
import eu.kanade.tachiyomi.util.view.inflate
import eu.kanade.tachiyomi.util.view.snack
import eu.kanade.tachiyomi.util.view.visible
import eu.kanade.tachiyomi.widget.AutofitRecyclerView
import kotlinx.android.synthetic.main.catalogue_controller.catalogue_view
import kotlinx.android.synthetic.main.catalogue_controller.progress
import kotlinx.android.synthetic.main.main_activity.drawer
import rx.Observable
import rx.Subscription
import rx.android.schedulers.AndroidSchedulers
import timber.log.Timber
import uy.kohesive.injekt.injectLazy
import java.util.concurrent.TimeUnit

/**
 * Controller to manage the catalogues available in the app.
 */
open class BrowseCatalogueController(bundle: Bundle) :
        NucleusController<BrowseCataloguePresenter>(bundle),
        SecondaryDrawerController,
        FlexibleAdapter.OnItemClickListener,
        FlexibleAdapter.OnItemLongClickListener,
        FlexibleAdapter.EndlessScrollListener,
        ChangeMangaCategoriesDialog.Listener {

    constructor(source: CatalogueSource) : this(Bundle().apply {
        putLong(SOURCE_ID_KEY, source.id)
    })

    /**
     * Preferences helper.
     */
    private val preferences: PreferencesHelper by injectLazy()

    /**
     * Adapter containing the list of manga from the catalogue.
     */
    private var adapter: FlexibleAdapter<IFlexible<*>>? = null

    /**
     * Snackbar containing an error message when a request fails.
     */
    private var snack: Snackbar? = null

    /**
     * Navigation view containing filter items.
     */
    private var navView: CatalogueNavigationView? = null

    /**
     * Recycler view with the list of results.
     */
    private var recycler: RecyclerView? = null

    /**
     * Subscription for the search view.
     */
    private var searchViewSubscription: Subscription? = null

    /**
     * Subscription for the number of manga per row.
     */
    private var numColumnsSubscription: Subscription? = null

    /**
     * Endless loading item.
     */
    private var progressItem: ProgressItem? = null

    init {
        setHasOptionsMenu(true)
    }

    override fun getTitle(): String? {
        return presenter.source.name
    }

    override fun createPresenter(): BrowseCataloguePresenter {
        return BrowseCataloguePresenter(args.getLong(SOURCE_ID_KEY))
    }

    override fun inflateView(inflater: LayoutInflater, container: ViewGroup): View {
        return inflater.inflate(R.layout.catalogue_controller, container, false)
    }

    override fun onViewCreated(view: View) {
        super.onViewCreated(view)

        // Initialize adapter, scroll listener and recycler views
        adapter = FlexibleAdapter(null, this)
        setupRecycler(view)

        navView?.setFilters(presenter.filterItems)

        progress?.visible()
    }

    override fun onDestroyView(view: View) {
        numColumnsSubscription?.unsubscribe()
        numColumnsSubscription = null
        searchViewSubscription?.unsubscribe()
        searchViewSubscription = null
        adapter = null
        snack = null
        recycler = null
        super.onDestroyView(view)
    }

    override fun createSecondaryDrawer(drawer: DrawerLayout): ViewGroup? {
        // Inflate and prepare drawer
        val navView = drawer.inflate(R.layout.catalogue_drawer) as CatalogueNavigationView
        this.navView = navView
        navView.setFilters(presenter.filterItems)

        drawer.setDrawerLockMode(DrawerLayout.LOCK_MODE_UNLOCKED, GravityCompat.END)

        navView.onSearchClicked = {
            val allDefault = presenter.sourceFilters == presenter.source.getFilterList()
            showProgressBar()
            adapter?.clear()
            drawer.closeDrawer(GravityCompat.END)
            presenter.setSourceFilter(if (allDefault) FilterList() else presenter.sourceFilters)
        }

        navView.onResetClicked = {
            presenter.appliedFilters = FilterList()
            val newFilters = presenter.source.getFilterList()
            presenter.sourceFilters = newFilters
            navView.setFilters(presenter.filterItems)
        }
        return navView
    }

    override fun cleanupSecondaryDrawer(drawer: DrawerLayout) {
        navView = null
    }

    private fun setupRecycler(view: View) {
        numColumnsSubscription?.unsubscribe()

        var oldPosition = RecyclerView.NO_POSITION
        val oldRecycler = catalogue_view?.getChildAt(1)
        if (oldRecycler is RecyclerView) {
            oldPosition = (oldRecycler.layoutManager as LinearLayoutManager).findFirstVisibleItemPosition()
            oldRecycler.adapter = null

            catalogue_view?.removeView(oldRecycler)
        }

        val recycler = if (presenter.isListMode) {
            RecyclerView(view.context).apply {
                id = R.id.recycler
                layoutManager = LinearLayoutManager(context)
                layoutParams = RecyclerView.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT, ViewGroup.LayoutParams.MATCH_PARENT)
                addItemDecoration(DividerItemDecoration(context, DividerItemDecoration.VERTICAL))
            }
        } else {
            (catalogue_view.inflate(R.layout.catalogue_recycler_autofit) as AutofitRecyclerView).apply {
                numColumnsSubscription = getColumnsPreferenceForCurrentOrientation().asObservable()
                        .doOnNext { spanCount = it }
                        .skip(1)
                        // Set again the adapter to recalculate the covers height
                        .subscribe { adapter = this@BrowseCatalogueController.adapter }

                (layoutManager as GridLayoutManager).spanSizeLookup = object : GridLayoutManager.SpanSizeLookup() {
                    override fun getSpanSize(position: Int): Int {
                        return when (adapter?.getItemViewType(position)) {
                            R.layout.catalogue_grid_item, null -> 1
                            else -> spanCount
                        }
                    }
                }
            }
        }
        recycler.setHasFixedSize(true)
        recycler.adapter = adapter

        catalogue_view.addView(recycler, 1)

        if (oldPosition != RecyclerView.NO_POSITION) {
            recycler.layoutManager?.scrollToPosition(oldPosition)
        }
        this.recycler = recycler
    }

    override fun onCreateOptionsMenu(menu: Menu, inflater: MenuInflater) {
        inflater.inflate(R.menu.catalogue_list, menu)

        // Initialize search menu
        val searchItem = menu.findItem(R.id.action_search)
        val searchView = searchItem.actionView as SearchView

        val query = presenter.query
        if (!query.isBlank()) {
            searchItem.expandActionView()
            searchView.setQuery(query, true)
            searchView.clearFocus()
        }

        val searchEventsObservable = searchView.queryTextChangeEvents()
                .skip(1)
                .filter { router.backstack.lastOrNull()?.controller() == this@BrowseCatalogueController }
                .share()
        val writingObservable = searchEventsObservable
                .filter { !it.isSubmitted }
                .debounce(1250, TimeUnit.MILLISECONDS, AndroidSchedulers.mainThread())
        val submitObservable = searchEventsObservable
                .filter { it.isSubmitted }

        searchViewSubscription?.unsubscribe()
        searchViewSubscription = Observable.merge(writingObservable, submitObservable)
                .map { it.queryText().toString() }
                .subscribeUntilDestroy { searchWithQuery(it) }

        searchItem.fixExpand(
                onExpand = { invalidateMenuOnExpand() },
                onCollapse = {
                    searchWithQuery("")
                    true
                }
        )

        // Setup filters button
        menu.findItem(R.id.action_set_filter).apply {
            icon.mutate()
            if (presenter.sourceFilters.isEmpty()) {
                isEnabled = false
                icon.alpha = 128
            } else {
                isEnabled = true
                icon.alpha = 255
            }
        }

        // Show next display mode
        menu.findItem(R.id.action_display_mode).apply {
            val icon = if (presenter.isListMode)
                R.drawable.ic_view_module_white_24dp
            else
                R.drawable.ic_view_list_white_24dp
            setIcon(icon)
        }
    }

    override fun onPrepareOptionsMenu(menu: Menu) {
        super.onPrepareOptionsMenu(menu)

        val isHttpSource = presenter.source is HttpSource
        menu.findItem(R.id.action_open_in_web_view).isVisible = isHttpSource
    }

    override fun onOptionsItemSelected(item: MenuItem): Boolean {
        when (item.itemId) {
            R.id.action_search -> expandActionViewFromInteraction = true
            R.id.action_display_mode -> swapDisplayMode()
            R.id.action_set_filter -> navView?.let { activity?.drawer?.openDrawer(GravityCompat.END) }
            R.id.action_open_in_web_view -> openInWebView()
        }
        return super.onOptionsItemSelected(item)
    }

    private fun openInWebView() {
        val source = presenter.source as? HttpSource ?: return

        val activity = activity ?: return
        val intent = WebViewActivity.newIntent(activity, source.id, source.baseUrl, presenter.source.name)
        startActivity(intent)
    }

    /**
     * Restarts the request with a new query.
     *
     * @param newQuery the new query.
     */
    private fun searchWithQuery(newQuery: String) {
        // If text didn't change, do nothing
        if (presenter.query == newQuery)
            return

        showProgressBar()
        adapter?.clear()

        presenter.restartPager(newQuery)
    }

    /**
     * Called from the presenter when the network request is received.
     *
     * @param page the current page.
     * @param mangas the list of manga of the page.
     */
    fun onAddPage(page: Int, mangas: List<CatalogueItem>) {
        val adapter = adapter ?: return
        hideProgressBar()
        if (page == 1) {
            adapter.clear()
            resetProgressItem()
        }
        adapter.onLoadMoreComplete(mangas)
    }

    /**
     * Called from the presenter when the network request fails.
     *
     * @param error the error received.
     */
    fun onAddPageError(error: Throwable) {
        Timber.e(error)
        val adapter = adapter ?: return
        adapter.onLoadMoreComplete(null)
        hideProgressBar()

        snack?.dismiss()

        if (catalogue_view != null) {
            val message = if (error is NoResultsException) catalogue_view.context.getString(R.string.no_results_found) else (error.message ?: "")

            snack = catalogue_view.snack(message, Snackbar.LENGTH_INDEFINITE) {
                setAction(R.string.action_retry) {
                    // If not the first page, show bottom progress bar.
                    if (adapter.mainItemCount > 0) {
                        val item = progressItem ?: return@setAction
                        adapter.addScrollableFooterWithDelay(item, 0, true)
                    } else {
                        showProgressBar()
                    }
                    presenter.requestNext()
                }
            }
        }
    }

    /**
     * Sets a new progress item and reenables the scroll listener.
     */
    private fun resetProgressItem() {
        progressItem = ProgressItem()
        adapter?.endlessTargetCount = 0
        adapter?.setEndlessScrollListener(this, progressItem!!)
    }

    /**
     * Called by the adapter when scrolled near the bottom.
     */
    override fun onLoadMore(lastPosition: Int, currentPage: Int) {
        if (presenter.hasNextPage()) {
            presenter.requestNext()
        } else {
            adapter?.onLoadMoreComplete(null)
            adapter?.endlessTargetCount = 1
        }
    }

    override fun noMoreLoad(newItemsSize: Int) {
    }

    /**
     * Called from the presenter when a manga is initialized.
     *
     * @param manga the manga initialized
     */
    fun onMangaInitialized(manga: Manga) {
        getHolder(manga)?.setImage(manga)
    }

    /**
     * Swaps the current display mode.
     */
    fun swapDisplayMode() {
        val view = view ?: return
        val adapter = adapter ?: return

        presenter.swapDisplayMode()
        val isListMode = presenter.isListMode
        activity?.invalidateOptionsMenu()
        setupRecycler(view)
        if (!isListMode || !view.context.connectivityManager.isActiveNetworkMetered) {
            // Initialize mangas if going to grid view or if over wifi when going to list view
            val mangas = (0 until adapter.itemCount).mapNotNull {
                (adapter.getItem(it) as? CatalogueItem)?.manga
            }
            presenter.initializeMangas(mangas)
        }
    }

    /**
     * Returns a preference for the number of manga per row based on the current orientation.
     *
     * @return the preference.
     */
    fun getColumnsPreferenceForCurrentOrientation(): Preference<Int> {
        return if (resources?.configuration?.orientation == Configuration.ORIENTATION_PORTRAIT)
            preferences.portraitColumns()
        else
            preferences.landscapeColumns()
    }

    /**
     * Returns the view holder for the given manga.
     *
     * @param manga the manga to find.
     * @return the holder of the manga or null if it's not bound.
     */
    private fun getHolder(manga: Manga): CatalogueHolder? {
        val adapter = adapter ?: return null

        adapter.allBoundViewHolders.forEach { holder ->
            val item = adapter.getItem(holder.adapterPosition) as? CatalogueItem
            if (item != null && item.manga.id!! == manga.id!!) {
                return holder as CatalogueHolder
            }
        }

        return null
    }

    /**
     * Shows the progress bar.
     */
    private fun showProgressBar() {
        progress?.visible()
        snack?.dismiss()
        snack = null
    }

    /**
     * Hides active progress bars.
     */
    private fun hideProgressBar() {
        progress?.gone()
    }

    /**
     * Called when a manga is clicked.
     *
     * @param position the position of the element clicked.
     * @return true if the item should be selected, false otherwise.
     */
    override fun onItemClick(view: View, position: Int): Boolean {
        val item = adapter?.getItem(position) as? CatalogueItem ?: return false
        router.pushController(MangaController(item.manga, true).withFadeTransaction())

        return false
    }

    /**
     * Called when a manga is long clicked.
     *
     * Adds the manga to the default category if none is set it shows a list of categories for the user to put the manga
     * in, the list consists of the default category plus the user's categories. The default category is preselected on
     * new manga, and on already favorited manga the manga's categories are preselected.
     *
     * @param position the position of the element clicked.
     */
    override fun onItemLongClick(position: Int) {
        val activity = activity ?: return
        val manga = (adapter?.getItem(position) as? CatalogueItem?)?.manga ?: return
        if (manga.favorite) {
            MaterialDialog.Builder(activity)
                    .items(activity.getString(R.string.remove_from_library))
                    .itemsCallback { _, _, which, _ ->
                        when (which) {
                            0 -> {
                                presenter.changeMangaFavorite(manga)
                                adapter?.notifyItemChanged(position)
                                activity?.toast(activity?.getString(R.string.manga_removed_library))
                            }
                        }
                    }.show()
        } else {
            presenter.changeMangaFavorite(manga)
            adapter?.notifyItemChanged(position)

            val categories = presenter.getCategories()
            val defaultCategoryId = preferences.defaultCategory()
            val defaultCategory = categories.find { it.id == defaultCategoryId }
            when {
                defaultCategory != null -> presenter.moveMangaToCategory(manga, defaultCategory)
                defaultCategoryId == 0 || categories.isEmpty() -> // 'Default' or no category
                    presenter.moveMangaToCategory(manga, null)
                else -> {
                    val ids = presenter.getMangaCategoryIds(manga)
                    val preselected = ids.mapNotNull { id ->
                        categories.indexOfFirst { it.id == id }.takeIf { it != -1 }
                    }.toTypedArray()

                    ChangeMangaCategoriesDialog(this, listOf(manga), categories, preselected)
                            .showDialog(router)
                }
            }
            activity?.toast(activity?.getString(R.string.manga_added_library))
        }

    }

    /**
     * Update manga to use selected categories.
     *
     * @param mangas The list of manga to move to categories.
     * @param categories The list of categories where manga will be placed.
     */
    override fun updateCategoriesForMangas(mangas: List<Manga>, categories: List<Category>) {
        val manga = mangas.firstOrNull() ?: return
        presenter.updateMangaCategories(manga, categories)
    }

    protected companion object {
        const val SOURCE_ID_KEY = "sourceId"
    }

}
